Sky Lake PCH contains two GSPI controllers. Using the common GSPI controller driver implementation for Intel PCH, add support for GSPI controller buses on Sky Lake/Kaby Lake. BUG=b:35583330 Change-Id: I29b1d4d5a6ee4093f2596065ac375c06f17d33ac Signed-off-by: Furquan Shaikh <furquan@chromium.org> Reviewed-on: https://review.coreboot.org/19099 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin <adurbin@chromium.org>